<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>提示框</title>
    <style>
        .demo .ts{
           visibility: hidden;
           position: absolute;
           z-index: 1;
           left: 0;
           bottom: -20px;
           width: 200px;
           height: 30px;
           background-color: rgba(0, 0, 0, 0.6);  
           color: aliceblue; 
        }
        .demo:hover .ts{
            visibility: visible;
        }
    </style>
</head>
<body>
    <div title="提示文本">DEMO文字</div>
</body>
</html>